ananyo writes "From a few fragments out of a collection of 23-century-old Chinese bamboo strips, historians have pieced together what they say is the world's oldest example of a multiplication table in base 10. Each strip is about 7 to 12 millimeters wide and half a meter long, and has a vertical line of ancient Chinese calligraphy painted on it in black ink. The bamboo pieces constitute 65 ancient texts and are thought to be among the most important artifacts from the Warring States period before the unification of China. But 21 bamboo strips contained only numbers and, on closer inspection, turned out to be a multiplication table. As in a modern multiplication table, the entries at the intersection of each row and column in the matrix provide the results of multiplying the corresponding numbers. The table can also help users to multiply any whole or half integer between 0.5 and 99.5. The researchers suspect that officials used the multiplication table to calculate surface area of land, yields of crops and the amounts of taxes owed."